Lynn A. Capadona

A versatile approach for the processing of polymer nanocomposites with self-assembled nanofibre templates

The incorporation of nanoparticles into polymers is a design approach that is used in many areas of materials science. The concept is attractive because it enables the creation of materials with new or improved properties by mixing multiple constituents and exploiting synergistic effects. One important technological thrust is the development of structural materials with improved mechanical and thermal characteristics. Equally intriguing is the possibility to design functional materials with unique optical or electronic properties, catalytic activity or selective permeation. The broad technological exploitation of polymer nanocomposites is, however, stifled by the lack of effective methods to control nanoparticle dispersion. We report a simple and versatile process for the formation of homogeneous polymer/nanofibre composites. The approach is based on the formation of a three-dimensional template of well-individualized nanofibres, which is filled with any polymer of choice. We demonstrate that this template approach is broadly applicable and allows for the fabrication of otherwise inaccessible nanocomposites of immiscible components.

Reinforcing polymer cross-linked aerogels with carbon nanofibers

We have previously reported cross-linking the mesoporous silica structure of aerogels with di-isocyanates, styrenes or epoxies reacted with amine decorated silica surfaces. These approaches have been shown to significantly increase the strength of aerogels with only a small effect on density or porosity. Herein, we examine the effect of including up to 5% (w/w) carbon nanofibers in the silica backbone before cross-linking. The addition of 5% carbon nanofibers to the lowest density aerogels studied triples the compressive modulus and the tensile stress at break is increased five-fold with no density penalty. The carbon fiber also improves the strength of the initial hydrogels before cross-linking, which may have implications in manufacturing.